Carrier for radioactive material



HUUWE Feb. 12, 1957 w. w. OFFNER CARRIER FOR RADIOACTIVE MATERIAL Filed Nov. 12, 1953 2 Sheets-Sheet l lllHHHllllIlJ INVENTOR. Wane/a W. OFFNER ATTO/i/VEV Feb. 12, 1957 w. w. OFFNER CARRIER FOR RADIOACTIVE MATERIAL 2 Sheets-Sheet 2.

Filed NOV. 12, 1953 FIG. 2

ATTORN EV My invention relates to means for facilitating the safe manual handling of radioactive material, particularly capsules or small bodies of radioactive material especially useful in industrial processes, such as radiographic inspection of castings and other similar light-opaque objects.

While the usual capsule of radioactive material; for example, radioactive cobalt, is not dangerous or harmful to handlers if only a relatively short duration of exposure occurs at infrequent intervals, there may be serious physical and physiological effects in the event the exposure to the emanating source is continued over a long time. It is necessary to provide shielding for those who are in close proximity to the source, yet the usual shielding materials, being quite heavy; such as lead, can be used in only relatively small quantities as the source and its shielding are necessarily portable by hand.

It is therefore an object of my invention to provide a carrier for radioactive materials in which the relatively heavy shielding is utilized to an optimum advantage.

Another object of my invention is to provide a portable carrier for radioactive material in which the possibility of mishandling the carrier is minimized.

Another object of my invention is to provide a carrier for radioactive material in which the shielding has a directional characteristic with the maximum protection to the customary user of the carrier.

A still further object of my invention is in general to improve carriers for radioactive material.

Other objects, together with the foregoing, are attained in the embodiment of the invention described in the accompanying description and illustrated in the accompanying drawings, in which:

Figure 1 is a front elevation of a carrier constructed in accordance with my invention.

Figure 2 is a side elevation of the carrier disclosed in Figure 1.

While the carrier of my invention has been successfully embodied in a device for the portable, manual handling of radioactive cobalt for industrial purposes, it is susceptible to variations and changes in accordance with the particular environment in which it is to be utilized.

In the present instance, the carrier is of a weight, size and shape for personal transportation or hand carrying by a user and includes a frame, generally designated 6, and having a base 7 for supporting the carrier, when not in use, on any suitable surface, such as the ground or a floor. The base 7 is preferably a circular metallic disc of any suitable material, such as steel, and is provided with an upstanding collar 8 integrally united thereto. The collar also serves as a junction point for a pair of upstanding straps 9 and 11 included in the frame and disposed substantially symmetrically at opposite ends of a diameter of the base 7 and collar 8. The upper ends of the straps 9 and 11 are terminated at the opposite ends of a tubular handle 12, conveniently of hollow metal, and of a diam eter to be conveniently grasped in the hand of a user. The structure as so far described is substantially symmetrical 2,781,455 Patented Feb. 12, 1957 about a central plane indicated by the center line 13 in Figure 1.

Retained by suitable means within the carrier 8 between the straps 9 and 11 is a body 14, preferably constructed of an appropriate shielding material; for example, lead. Since lead is very heavy and the ability of a user to carry much bulk of lead is limited, the body 14, in order to retain as much as possible of a favorable shape, is made substantially spherical with the center 16 of the sphere approximately on the axis or center line 13. The sphere is retained in position in part also by a reinforcing strap 17 which extends between the straps 9 and 11 and is removably secured thereto by appropriate fasteners 18 and 19.

The body 14 is provided with means for holding a radioactive substance and for that reason is shaped to provide an interior, circular cylindrical cavity 21. The cavity is of an appropriate size to receive a capsule 22 containing the radioactive material and extends inwardly from the upper, relatively flat face 23 of the body at an appropriate angle. A groove 24 in the body alongside the cavity and in the surface 23 affords room for the passage of a chain 26 secured to the capsule and provided for handling by tongs or the like. An appropriate lead stopper 27 overlies the surface 23 and has a boss 28 extending into the cavity 21 and occupying the portion thereof not substantially occupied by the capsule 22. A guard chain 29 is secured to the stopper 27 and also is held by a fastening 31 on the strap 11.

In accordance with my invention, the cavity 21 is not disposed symmetrically within the body 14 with respect to the center line 13, but, rather, is on one side of the center line and is, in fact, on one side of a plane going symmetrically through the center line and through the straps 9 and 11. The reason for offsetting or asymmetrically disposing the cavity 21 is in order to maintain it optimum or maximum amount of shielding between the capsule 22 and one side of the frame. That is, as seen in Figure 1, there is a maximum amount of shielding between the capsule and the right-hand side of the figure. Truly enough, there is a minimum amount of shielding between the capsule and the left-hand side of the frame but that is of little importance. Because the capsule 22 can be considered as a point source of radiation, the maximum amount of shielding is toward the right, as seen in Figure l, with disminishing amounts toward the left-hand side. Since the necessity for shielding in a downward direction is not great, the bottom of the body 14- is truncated at an inclination 32 with the truncation being also asymmetrical so that no substantial amount of the right-hand portion of the shield is removed although weight is reduced.

Because of the oriented or asymmetrical nature of the cavity 21 with respect to the framework 6, I especially provide a guard 33 for the handle 12 so that it will be impossible for a user intending to carry the radioactive material to pick it up in any way except with the maximum shielding between himself and the capsule 22. For that reason, I provide a curved plate 34 having one end extending entirely along the top of the tubular handle 12 and curved around to provide a depending flange 36 at its lower end spanning the distance between and secured to the straps 9 and 11. Preferably, the ends of the handle guard are closed in by plates 37, and the radius or curvature of the guard 33 is such and its inclination as it appreaches the straps 9 and 11 is such that the ordinary or usual user cannot in any fashion appropriately grasp in his hand, or between his palm and fingers, any portion of the guard 33. Instead, the guard 33 in effect provides a barrier or stop so that only by introducing his fingers underneath the handle tube 12 from the left-hand side, as seen in Figure 1, and wrapping his fingers substantially o around the handle from that side can the user effectively grasp the handle and lift up the frame 6 so that the shielding body 14 depends therefrom.

In other words, the guard 33 is on one side of the center line or central plane 13, whereas the cavity 21 is on the opposite side of that center or plane. For that reason, a user grasping the handle 12 and picking up the carrier must necessarily have the maximum shielding between the capsule and himself. The thickness of the shielding below the capsule near the truncated portion 321's such that adequate protection is afforded the users feet or legs; in fact, his entire body is afforded maximum protection. Furthermore, the plug 27 and boss 28 afford an extra thickness of shielding metal at the top of the body 14 to afford an extra measure of protection in an upward direction.

Since the user walks along carrying the carrier in one hand, he must necessarily always do so with the maximum shielding toward himself. While he may occasionally pass others in Walking who are subjected to the radiations from the source within the cavity 21 and while such others are afforded only a minimum amount of shielding, still the time of their exposure to the radioactive material is extremely short compared to the time during which the user is exposed and hence the danger to others is adequately relieved by the amount of shielding provided for them.

At its point of use, the capsule 22 is removed from the carrier by removal of the stopper or plug 27 and use of the chain 26 and when restored after use is again available for carrying. The carrier can be picked up or grasped in the dark or even inadvertently in only one orientation so as to provide always the maximum shielding between the source and the user while it is being carried.

Additionally, the handle 12, being approximately parallel to the ground and parallel to the direction of advance of the user, and being rigidly connected with the shielding body, prevents undue swaying or motion of the carrier in use and this effect is augmented because of the great weight of the shielding body. Thus, there is little or no tendency for the carrier to turn or twist or be oriented in any way to increase to any marked extent the amount of radiation to which the user is subjected.

What is claimed is:

l. A carrier for radioactive material comprising a frame, a handle at one end of said frame, a body of shielding material at the other end of said frame, said body being disposed to depend below said handle when said handle is grasped in the hand of a user, a guard on said frame for preventing the user from grasping said handle from one side thereof, and means in said body in a fixed location remote from said one side for receiving a radioactive substance.

2. A carrier for radioactive material comprising a frame, a handle at one end of said frame, a body of shielding material at the other end of said frame, said handle and said body being substantially symmetrical about a central plane, means on said frame on one side of said plane for preventing hand grasping of said handle by a user from said side of said plane, and means in said body in a fixed location on the other side of said plane for containing a radioactive substance.

3. A carrier for radioactive material comprising a frame, means for supporting said frame on the floor, a handle on said frame parallel to the floor, a body of shielding material on said frame, there being a fixed cavity in said body asymmetricaly disposed therein relative to said handle, and a guard on said frame blocking engagement of a users fingers with said handle except from the side thereof on which said cavity is disposed.

4. A carrier for radioactive material comprising a frame, means for supporting said frame in an upright position, means for holding a radioactive substance in a fixed location on said frame, a body of shielding material on said frame on one side of said holding means, and a handle on said frame above said holding means and engageable by a users fingers only from the side opposite said shielding material.

References Cited in the file of this patent UNITED STATES PATENTS 2,477,648 Piggott et a1. Aug. 2, 1949 2,514,909 Strickland July 11, 1950 2,551,491 Gilks May 1, 1951 2,675,487 Schallert et al Apr. 13, 1954 2,719,926 Procter et al Oct. 4, 1955 

